Shane Carruth's first movie, "Primer," takes all the paradoxes and mind-bending possibilities of time travel and distills them into one 77-minute-long head trip. If you saw it, you're probably still trying to figure out what that all was about. Carruth wrote, directed, shot, starred in, and composed the score for the movie, making him easily one of the most independent of all independent filmmakers out there.

Carruth's follow-up movie, "Upstream Color," is much stranger and more biological. If David Cronenberg and Terrence Malick ever got together and made a movie, it might just look something like this. The world that Carruth creates is as maddeningly opaque as it is compelling. This is not a flick that is easily summarized, but it centers on Kris (Amy Seitz), a woman who, after suffering a devastating if baffling crime, finds herself seeking out safety and comfort in the equally damaged Jeff (Carruth). But they both seem to be part of a surrealist ecosystem that involves worms -- which petty thugs use to create some kind of mind-controlling drug. And there are those menacing blooms of blue organisms. And a band of orchid thieves. And then there's that pig farmer who may or may not be God. '

Whether you love the film or are perplexed by it, you can be sure that everything on the screen is there because Carruth wanted it to be so. As with "Primer," he wrote, directed, edited, sound-edited, and starred in this film, and it very much feels like the product of a singular vision.

I talked with Carruth at a bustling bar in Austin, Texas, during the SXSW Film Festival last month. He comes across as someone who is exceedingly intelligent but sometimes has trouble keeping up with his brain. We talked about worms, identity, and being a control freak.

JC: It's a lot to unpack. [Laughs.] So you tell me about the process of writing this?

Filmmaker Shane Carruth (Larry Busacca/Getty Images)

SC: It started as a fun little thought experiment. I wanted to explore personal identity and where that comes from and whether behavior dictates identity or whether identity dictates behavior. The more I drilled down into it, the more it seemed like the way that I would see the world and the world would see me is all dependent on identity. Whether I'm a good or bad person, how my morality works. Everything is identity. So I started playing with the idea of stripping somebody of their identity and having them rebuild it wrong. That's when the story really hit the ground, and I knew I really needed to make it.

JC: Rebuild their identity.

SC: With the wrong information. Not be able to atone for what it looks like they must have done and then have to decide that, "Oh, then I must be this kind of person." Chris thinks that she must be a very crazy person. She must be someone who needs prescription drugs and therapy.

But what was really important is that I've got these characters. I have to have some way just to get them to wake up in a moment where they can't understand how they got there or why, and they built it wrong. That suspicion that whatever I think I am right now is possibly not quite right. I needed that to constantly be underneath.

And to get back to what you're saying with the pigs and the worms and the orchids, I developed this life-cycle thing basically so that the characters could continue to be affected at a distance. That's my solution to how to do this. I needed for this system to feel like it's been here as long as anybody has been here and that it's cyclical. Then its cycle is maintained not by conspiracy but by these three points in the triangle that are just continuing to do the thing that comes natural to them. The thief has found a way to use this worm. He's going to continue to use it. A pig farmer or a sampler wants to create this emotional -- this goldfish bowl full of emotional experiences, so that's what he does, and he's not thinking about the other two.

JC: And the third party is the victims, right?

SC: Well, the third would be the orchid harvester.

JC: The orchid harvesters, right.

SC: Yeah. And so the victims are at the center of the storm that they don't know what's happening around them.

JC: How do you see this movie connecting with your previous movie "Primer"?

SC: Yeah, it's weird. "Upstream" is a really ambitious thing, and I just think it is a far, far better movie technically or in any way. I mean, it's just mature, and I think it's more mature and better. When I first started talking about this movie, I was like, "They're not connected at all." But then it was brought to my attention that there are some common things with both movies, and now I feel silly saying that they're not connected at all. But I certainly didn't intend for them to be. I know that.

JC: I mean, both movies are extremely personal. Like "Primer," you wrote, directed, produced, and starred in your movie. I'm probably missing a couple of credits. And for this movie, you're even distributing it, too. Why do you feel like you need that much control over the product? Isn't that insanely stressful?

SC: It is. I'm really naive. I tried to do something out of necessity, like doing the music. But I'm slowly getting to the point where I'm realizing that I'm not the best person in the world to be doing any of the things that I try to do. I'm not even the best writer. I'm not the best director. I'm not the best cinematographer, and I'm certainly not the best composer. But my hope is that if my hands are in all of these things, I can keep it unified. As an audience member, I like works that I know I can trust that have been rigidly thought out and that are very singular in intention. If a character does something and it seems odd to me, I like to be able to know I can dwell in that and think about that and come to some conclusion. With movies that are just sort of written by one guy, then rewritten by another guy, then rewritten by another guy, and then all of these elements come together from different places, I don't feel like as an audience member I can do the work. If I see something odd happened, I'll just think that that's probably the rewrite.

JC: So tell me, "Primer" came out in 2004. Why the lag between this movie and the last one?

SC: I was trying to get something else made that was very expensive. Not very expensive; it was more expensive, obviously, than I could raise. Or else I would have done it. It's called "A Topiary." It was a really wonderful story, I think, but it required effects, and I spent a lot of time designing the world and how it worked. After I spent a year doing meetings that really weren't going anywhere, all the elements for "Upstream Color" started to come together in my mind. I dropped the other thing completely and threw myself into this. And, luckily, this is something that I did not pitch to anybody. I could just say, "We're going to do this."

JC: So is "A Topiary" dead, even if somebody gave you a pile of money?

SC: That would never happen. They would say, "If there's a large chunk of money, let me read the script; I'm going to see what we can do. Maybe we can have some foreign pre sales to augment the risk.We'll be taking meetings with…" It's just horrifying. Horrifying. [Laughs.]

JC: So for your next movie, are you going to do everything on your own again?

SC: I know that I'm a control freak. I want to write the music, and I want to do all the things that I do. What I need to hire are really wonderful technicians and department heads to take care of the 90 percent of the job. I don't need to be the guy that knows that we need a software upgrades for the editing software.